I've been scouring the internet looking for whether or not this is even possible.
Seems rudimentary to me, CUCM doing basic connection tracking, and sending TBCT commands via MGCP to the router and subsequently to the service provider via the D channel. Scripts, either TCL or VXML shouldn't even come into play.
So, my questions are...
1. is this even possible via MGCP
2. why won't TAC offer assistance with this
3. why if CUCM is at v 10.5 - hasn't this been implemented as a mature feature